Theoretical models have been formulated describing the spread of foam on burning liquid fuel surfaces in pool-like configurations. The main driving force of the foam spread is due to differences in the hydrostatic pressure within the foam while the dominating resisting force is due to viscous friction between the foam blanket and the fuel beneath. Account is taken to the influence of ordinary drainage, radiation-induced drainage, and evaporation. A large number of experiments have been performed to generate input data and to generate data for verification of the theoretical models. A series of experiments with water as “fuel” in a ½-symmetric pool has been used to determine friction coefficients. These coefficients have then been scaled and used for other fuels to calculate the foam spread in a number of different scenarios, both with and without fire. There is in general a good agreement between the calculated and the experimental results.